Lubricants



Patented Apr. 19, 1949 LUBRICANTS Eugene Lieber, New York, N. Y., and Martin M.

Sadlon, Roselle Park, N. J., assignors to Standt Company, a corporation ard Oil Developmen of Delaware No Drawing. Application August 4, 1945, Serial No. 609,042

2 Claims.

This invention relates to the preparation of novel lubricating compositions, and to the preparation of certain novel additives for such purposes. More particularly, the invention relates to a new method of lowering or depressing the pour point of Waxy mineral lubricatin oil.

Many different problems are involved in the production of waxy mineral lubricating oils which will pour or flow readily at low temperatures such as those encountered in cold climates or even in winter time in warmer climates. One way of partially solving this problem is to de- Wax the oil, but this is expensive and in certain respects reduces the quality of the oil. Another method, which may either be used alone or in conjunction with a light dewaxing, is to add to the waxy lubricant a small amount of substance called a pour depressor which modifies the properties of the waxduring crystallization and prevents the growth of the long, needle-like crystals, the inter-locking of which is primarily responsible for the apparent solidification of the oil.

In the use of such pour depressors,.it is known that sometimes a pour depressor will have relatively good potency in some waxy lubricating oil base stock and yet relatively poor potency in other waxy mineral lubricating oil base stocks. It is also known that two or more different pour depressors having relatively the same pour-depressor potency as tested by the standard A. S. T. M. pour point tests may be quite different in regard to their pour stability, as-measured by the Test V procedure as described in the procedures set forth on page 103 of "Oil and Gas Journal, vol. 42, June 24, 1943, using the operations labeled Figured One object of the present invention is to overcome these and other difiiculties encountered in the commercial utilization of pour depressors. Another object is to effect a general improvement in the potency of pour depressors.

The present invention is based-upon the dis covery that the potency of pour depressors can be very markedly improved=byincorporating into the pour depressor itself prior to the addition to the waxy lubricating oil, or adding it directly to the waxy lubricating oil, or both, a substance which in itself has no pour depressing properties, but which acts in some unknown manner to improve the sensitivity of the lubricating oil to the effect of a pour depressor. For convenience, this special additive or improving agent will be referred to as a pour sensitizer. The use of this pour sensitizer has in some instances effected an improvement in the potency of a pour depressor when added to all lubricating oil base stocks, but in most cases the improvement effected by the pour sensitizer is approximately inversely proportional to the original sensitivity of the lubricating oil base stock to reduction in pour point by the addition of the particular pour depressor concerned. In other words, if a certain lubricating oilbase stock is already highly sensitive to great reductions in pour point by the addition of a certain pour depressor, then the use of a pour sensitizer will effect only a moderate improvement or further reduction in A. S. T. M. pour point; and on the other hand, if thelubricating oil base stock is not very sensitive to, i. e. does not respond readily to improvement by, a pour, depressor, then the use of the pour sensitizer of this invention will ordinarily effect an astoundingly great improvement in the effectiveness of the pour depressor. This is so much the more surprising because'the pour sensitizer itself has little or no pour-depressing properties per se. Although the mechanism of the operation of the invention is not Well understood, it is believed that the pour sensitizer acts in some way to modify the solubility relationship of the pour depressor, the lubricating oil, and the waxy constituent contained therein. It may perhaps act somewhat like a plas ticizer or a mutual solvent for the pour depressor and the lubricating oil base, in some way as to enable the pour depressor more effectively to coat or adsorb upon the wax crystals promptly after their initial formation.

Since this pour sensitizer also effects a substantial improvement in the pour stability of waxy lubricating oils containing a pour depressor, which means that it enables them to better withstand alternate warming and cooling without becoming solid, the pour sensitizer may also act in some manner to accelerate solution of the pour depressor or perhaps the waxy constituents when a treated oil is warmed from below to above the melting point of the waxy constituent contained in the oil.

A great many different tests have been made in an attempt to find the boundary line between those chemical substances which do work as pour sensitizers and those which do not, and although it is difiicult to define these limits with great exactness, certain general rules can be laid down which will serve as a general guide as to all types of compounds, and it will be shown how they apply specifically in the case of certain preferred classes of chemical compounds.

In general, it is believed that the pour sensitizers of this invention should have a molecular weight between the approximate limit of 200 to 800, preferably about 250 to 750, and better still, about 300 to 700. These products should also have a boiling point above about 100 C., preferably above about 150 C. They may be either liquids or solids, depending upon their chemical nature.

In an earlier patent, U. S, 2,352,213, over which the present invention is an improvement, We have already shown that it is possible to extract from petroleum a particular fraction which has this pour sensitizing effect, but it has now been found how this invention may be applied to non-petroleum hydrocarbons, or more generally, to nonpetroleum compounds. Either pure organic compounds may be used or synthetic compounds or products may be made, or mixed commercial products available on the market may be used as such or after physical or chemical treatment to obtain best results according to the teachings of the present invention.

A number of different non-petroleum hydrocarbon products may be used according to this invention. For instance, a surprisingly efiective pour sensitizer may be obtained by solvent extraction, distillation, or by other suitable means, from inert fractions of aliphatic-aromatic condensation products, made for instance by Friedel- Crafts condensation of chlorinated wax with naphthalene. By inert fractions, it is intended to mean fractions which do not per se have any pour-depressing characteristics. In recovering the desired pour sensitizer fractions, the recovery procedure should be adapted to obtain condensation products having a relatively high aromatic/wax ratio. In the normal production of pour depressors by condensation of chlorinated wax with naphthalene in the presence of aluminum chloride, and generally in the presence of an inert solvent such as a refined kerosene or a halogenated hydrocarbon solvent such as tetrachlorethane, after the reaction is completed, it is customary to hydrolyze and remove the catalyst and then subject the reaction mixture to distillation under reduced pressure, i. e. fire and steam distillation up to about 600 F. or vacuum distillation, in order to remove the solvent and lowboiling product and to recover the desired pour depressor as distillation bottom. According to the present invention, it is preferred to obtain a pour sensitizer fraction by the following general procedure:

The wax-naphthalene condensation product,

made for instance by the Friedel-Crafts condensation of parts of a chloro-wax (containing about 13.5% chlorine and prepared from -120 F. M. P. paraffin wax) and 15 parts of naphthalene, is agitated at room temperature with a solvent comprising 12 parts of secondary amyl alcohol and 1 part of a heavy naphtha petroleum fraction in the ratio of 1000 ml. of Wax-naphthalene condensation product to 3000 ml. of solvent and allowed to settle until a clear upper layer has formed. This clear upper layer is then separated from the heavy bottom layer. The pour sensitizer" is then obtained from the clear upper layer by removing the solvent by conventional vacuum distillation. Usually three or four solvent treats are required to obtain the total yield of pour sensitizer material, from the original waxnaphthalene condensation product.

Other synthetic, aliphatic-aromatic hydrocarbon condensation products may be used such as made by Friedel-Crafts condensation of chlorinated parafiin wax with benzene or with diphenyl, or with other aromatic compounds such as: naphthalene, anthracene, toluene, xylene, triphenyl, phenol, phenyl-phenol, alpha-naphthol, aniline, quinoline, etc., provided the aromatic/wax ratio is high enough to produce condensation products having no A. S. T. M. pour depressor properties. Instead of using wax as the aliphatic hydrocarbon constituent, chlorinated or olefinic derivatives of other aliphatic hydrocarbons may be used, preferably having more than 6 carbon atoms, such as: octyl chloride decylene, lauryl alcohol, distearyl ketone, cracked parafiln wax, the polymeric isobutylenes (dimer, trimer, tetramer, etc), kerosene, etc.

Instead of using a pure or synthetic hydrocarbon pour sensitizer, many other non-petroleum organic compounds and products may be used. Esters constitute a very suitable class of materials for this purpose. For instance, one may use fatty acid esters of aliphatic alcohols, such as amyl stearate, lauryl oleate, amyl acetate, sec-butyl acetate, octyl butyrate, ethyl acetoacetate, triethylene glycol di-Z-ethyl hexoate, di-(2-ethyl hexyl sebacate) etc., or fatty acid esters of cyclic alcohols or phenols, e. g. benzyl stearate, phenyl stearate, phenyl oleate, di-a-myl phenyl acetate, etc., or esters of aromatic acids, e. g. hexyl benzoate, di-amyl phenyl benzoate, dimethyl phthalate, dibutyl phthalate, or esters containing a heterocyclic nucleus such as tetrahydrofurfuryl phthalate, tetrahydrofurfuryl oleate, etc., or esters of polyhydroxy alcohols, e. g. glycol laurate, glycol oleate, glycerol laurate, or esters of other types such as those containing non-ester oxygen, which may be present in the form of keto or ether linkages, etc., e. g. normal butyl levulinate which is the butyl ester of aceto-propionic acid, diglycol laurate, esters of mixed ketones, etc. Various rosin esters may be used such as methyl abietate, hydrogenated methyl abietate, pentaerythritol abietate, glyceryl ester of hydrogenated rosin, phenol abietate, methyl ester of tall oil, octadecyl ester of tall oil, etc.

The pour sensitizer may also be an ether compound, preferably an aliphatic-aromatic ether such as acetophenone, decyl-phenyl ether, ethylna-phthyl ether, or an alkylated aromatic-aliphatic ether such as p-amyl phenyl ethyl ether, p-lauryl phenyl naphthyl ether, etc. Aliphatic ethers may also be used, but in this case, it is preferable that they have more than 6 Cs/O. For instance, di-normal butyl ether may be used, or mono-ethyl ether of diethylene glycol. Other aromas suitable ethers include: mono-butoxy dlethylene glycol oleate, phenoxy-dipropyl-ene glycol, etc.

Ketones may also be used, and preferably they should be aromatic-aliphatic ketones such as stearyl phenones, oleyl ketone of naphthalene, heptadecyl ketone of naphthalene, and various ketones having the general formula A1(COR)1:, where R is a fatty or naphthenlc acid radical, and n is 1, 2 or more, e. g. phenyl ketone of petroleum naphthenic acid of the gas oil boiling range.

Other types of organic compounds which may be used as pour sensitizers include certain alcoholic compounds such as di-amyl cyclohexanol, and alkylated phenolic compounds such as a Friedel-Crafts condensation product of chlorinated paraflin wax with phenols, which condensation product is however inert as to pour-depressing properties per se.

In carrying out the invention, it is desirable to use about 1 to 100 parts, preferably about 5 to 50 parts by weight of pour sensitizer for every parts by weight of the pour depressor. These two materials may be first mixed together, and then later added in desired proportions to the lubricating oil base stock to be used, or the two materials may be separately added to the lubricating oil base stock. The concentration of the pour depressor and the pour sensitizer may vary in respect to each depending upon their particular nature and their relative effectiveness, but normally the concentration of each of these materials will be within the approximate limits of about .02% to 2.0% and generally within the narrower limits of about 0.1% to 1.0%.

The pour depressor to be used according to this invention may be selected from a wide variety of different types of substances. The invention has been found to apply particularly when the pour depressor used is a high molecular weight Friedel-Crafts condensation product of chlorinated paraffin wax with an aromatic compound such as an aromatic hydrocarbon or a hydroxy or amino derivative thereof, such as phenol. Examples of such pour depressors are the products made by condensing chlorinated parafiin wax having a chlorine content of about 10% to with naphthalene, using about 10 to parts by weight of naphthalene per 100 parts of chlorinated paraflin wax, in the presence of aluminum chloride as condensation catalyst, and preferably in the presence of an inert solvent such as a refined kerosene or tetrachlorethane, with subsequent hydrolysis and removal of residual catalyst as a sludge and distillation of the condensation product under reduced pressure, such as by fire and steam distillation up to 600 F., or under a vacuum corresponding to about 10 to 50 mm. mercury absolute pressure, to recover the desired pour depressor as distillation residue. A similar procedure may be used for making a pour depressor by condensat on of chlorinated paraifin wax with phenol. Either of the above two types of pour depressors may be further modified, if desired, by acylation, e. g. by stearyl chloride or other suitable acylating agents.

Other types of pour depressors to which the invention may be applied include the following types:

Polymeric esters, such as the poly-acrylates, e. g. polycetylalphamethacrylate, poly-vinylates, polybasic-acid-alcohol condensates, etc.

Fatty acid derivatives, such as metallic soaps,

e. g. aluminum stearate, fatty acid amides, mixed ketones, polymerized fatty acids, fatty acid do:-

6 rivatives oiE resins of the phenolic, cumar, indene, styrene, etc., type or their copolymers;

By-product types as cracking oil tar, components of pitch, etc.

Vinyl ether derivatives, such as the polymerized vinyl ethers of fatty alcohols.

Pour depressors from paraffin wax itself, for example, oxidized paraffin wax, polymerized chloro-wax.

Pour depressors derived from aromatic compounds themselves, for example. aromatic hydrocarbons are polymerized with A1C13.

Reaction products of olefins, e. g. cracked paraflin wax reacted with aromatics, vapor phase cracked gasoline polymerized with A1Cl3, etc.

Rubber derivatives which may comprise hydrorubber, rubber modified by amphoteric metal halides, unvulcanized rubber plasticized with peptizing agents, e. g. phenyl hydrazine, rubber condensed with-various types of organic compounds, e. g. chloro-hydrocarbons, aromatic compounds, etc.

Pour depressants formed by action of silent electric discharge on hydrocarbon oils, fats, esterwaxes or products of low oxygen content (voltolized products).

Chlorinated polymers, e. g. chlorinated polybutene, polyacrylate, poly-vinyl ethers, polystyrene, polycumarone, polyindene, etc., condensed with aromatic compounds.

Metallic derivatives of paraffin-wax aromatic compound condensation products.

It is intended that the invention be applied to any of the various available lubricating oil base stocks, but it is particularly applicable to oils which have peculiar properties in regard to their response to the action of commercially available pour depressors. Such oils may have peculiar pour point properties themselves, but may also be particularly sensitive to the type of pour depressor used, or, for the same pour depressor, to slight variation in the mode of synthesis. One such peculiar lubricating oil base stock is one derived from a Mid-Continent crude, which is mixed base, i. e. parafiinic-naphthenic base oil. The fraction showing the most peculiar pourdepressing response is a distillate having a viscosity base commonly referred to as S. A. E. number 10, and having approximately the following physical characteristics:

A. S. T. M. pour F. +5 A. S. T. M. cloud F. +12 Saybolt viscosity at F. 168.5 Saybolt viscosity at 210 F. 44.3

In the large amount of experimental data presented herebelow, this particular Mid-Continent oil will be referred to frequently because of its peculiar nature and because the invention has been found to be surprisingly effective in makin it possible to produce oils having low pour point and good pour stability from this base stock, which has proven to be one of the most difficult to use commercially.

In comparing the effectiveness of various pour depressors, which often vary in effectiveness according to the concentration in which they are used, it has proved practical to determine the susceptibility number. This number is obtained by adding the pour point depression in degrees Fahrenheit as obtained by A. S. T. M. pour point tests as absolute values over the entire range of concentrations tested, e. g., an oil with a natural po nt of +5 F., and having a pour point of -10 F. with a 0.4% concentration of additive, would have an absolute depression in pour point of 15 F. The sum of these absolute values over the range of concentrations of additives, obtained by testing in 10 increments of 0.1% each, gives the susceptibility number. Table I sets forth the pour points obtained with various concentrations ranging from 0.1% to 1.0%, and the total susceptibility number, for four different samples of pour depressor A and one of pour depressor B and one of pour depressor C, all in a lubricating 011 base stock consisting of the particular Mid-Continent oil referred to above.

TABLE I Per Cent Additive A-l A-2 A-3 A4 I B i c 1.0 -35 -25 -s --25 -20 -15 0.9.. -s5 -25 -30 -25 -20 0.8... -35 -25 -25 -25 -15 -15 0.7.. -20 +10 -10 -10 0.0. -20 -10 -20 -5 -10 -10 0.5 -10 0 0 0 -5 -5 0.4 10 +5 0 +5 +5 051:. 0- +5 +5 +5 +5 +5 +5 0.2 +5 +5 +5 +5 +5 +5 0.1 +5 +5 +5 +5 +5 +5 Susceptibility No 200 140 160 120 115 105 The pour depressors referred to m Table I may be briefly described as follows. Pour depressors A-l, A-Z, A-3 and A-4 were all made by the same general procedure by adding about 15 parts by Weight of naphthalene and about 2% parts by weight of aluminum chloride to about 40 parts by weight of a refined kerosene solvent, and adding about 100 parts by weight of chlorinated paraffin wax having a chlorine content of about 13% to 14%, starting the reaction at room tern perature and then after addition of all of the reactants, gradually heating the mixture to a final reaction temperature of about 90 which has been maintained for about 5 to 6 hours. It noted that although these four pour depressors an, i i-2, A- and A-4 all had about the same pour-depressing potency when used in low concentrations ranging from 6.1% to 0.3%, they showed some variation in potency when used in larger concentrations up to 1%, these variations perhaps being due to slight changes in technique of synthesis, i. e., lack of control over certain variables, slight changes in composition of wax, etc.

Pour depressor B was made from the same reactants and catalyst as used in making pour depressors A-l to 4, but instead of using a refined kerosene as solvent for the reaction, a chlorinated hydrocarbon solvent, specifically tetrachlorethane, was used.

The method of recovering the pour depressor was the same for pour depressors A-l to 4 and B, namely, that after the reaction was completed, the catalyst was hydrolyzed by adding aqueous NaOH and a mixture of water and isopropyl alcohol, and settling out the catalyst sludge, decanting the solvent solution of the condensation prodnot and subjecting the latter to distillation under fire and steam up to a temperature about 600 F.

Pour depressor C was a commercially available pour depressor, the manufacturing details of which are not known with certainty, but which is believed to have been made by condensing chlorinated parafiin wax with phenol in the presence of aluminum chloride, followed by hydrolysis and distillation steps similar to those used in preparing pour depressors A-l to 4 and B.

The data from Table I may be summarized as follows:

These data clearly indicate that pour depressors B and C have the poorest pour-depressing potency in this Mid-Continent lubricating base stock. On the other hand, when the pour depressor distillation bottoms obtained as described above, are blended with a small amount of a parafiinic lubricating oil base stock to make a pour depressor concentrate of standard potency, pour depressors A-l to 4 and B are found to have blending potencies which are almost exactly in inverse relation to the susceptibility number as determined in the Mid-Continent lube oil base stocks, and almost directly proportional to-the molecular weight of the pour depressor, as shown in the following data:

1 Of still bottoms.

Thus, it requires only 11% of pour depressor B distillation bottoms but requires 24% of pour depressor A-l distillation bottoms, to make in each case a concentrate of standardized pour-depressor potency, pour depressor B being obviously much more potent than pour depressor A-l; yet the susceptibility number in the Mid-Continent lube oil base stock indicates precisely the reverse that pour depressor A-l is much more potent than pour depressor B.

It had heretofore been proposed to subject the crude pour depressor distillation bottoms to solvent extraction with a wax-precipitant type of solvent, e. g. amyl alcohol, in order to selectively extract therefrom a low molecular weight inert fraction having substantially no pour-depressin properties whatsoever and to leave as rafiinate a fraction having an extremely high pour-depressing potency.

EXAMPLE 1 Such a solvent fractionation was applied experimentally to the pour depressor B distillation bottoms, using the preferred procedure previously described. Surprisingly, this inert raiiinate, having no pour-depressing properties whatsoever, was found to have a vow unexpected pour sensitizing effect. For instance, when blending 11.5% by volume of pour depressor B distillation bottoms with 88.5% of blend oil to make a concentrate of standardized pour-depressing potency, if various percentages of the blend oil are replaced by some of the inert extract which had an average molecular weight of about 500 and was obtained as described above, the pour susceptibility of the resultant blend when added in concentrations ranging from 0.1% to 1.0% to the Mid-Continent lube oil base stocks referred to above, increase in value almost directly proportionately; ,tothe amount of inert extract used. These data are shown in Table II.

TABLE II $3? g ggggf 53235512 Re lace by 1 our susceplne t extract "mtmenhm tibility None 115 Thus, if 11.5% of pour depressor B distillation bottoms with 88.5% of ordinary parafiinic blend oil, which is a Penn type of light lubricating oil having a viscosity of about 170 Saybolt at 100 F., to make a concentrate of standardized pourdepressing potency when used with ordinary paraffinic lubricating oil base stock, this concentrate has a pour susceptibility in the Mid-Continent oil base stock of only 110, whereas if 52% of the blend oil (i. e 52% of 88.5%) is replaced by low molecular weight inert extract from pour depressor B distillation bottoms, the resultant modified concentrate has a pour susceptibility of 255 in the Mid-Continent oil base. This is a 132% increase in pour susceptibility, and this astounding improvement is obtained, for some unknown reason, by addin inert material which has no pour-depressing property whatsoever.

EXAMPLE 2 of the same inert extract used in the above example was added to the commercial pour depressor C, which by itself showed a pour susceptibility of 105 in the Mid-Continent lube oil base stock, and it was found that the addition of the 15% of inert extract raised'the pour susceptibility from 105 to 175, again a very surprising increase.

EXAMPLES 3' AND 4 It was thought that perhaps the inert extract from pour depressor B distillation bottoms may act as a plasticizer for the more active portion; several known forganic plasticizers were tested in a manner similar to that used in Example 1, namely by replacing 21% of the blend oil used to blend 11.5% of pour depressor B distillation bottoms up to a concentrate having a standardized pour-depressing potency. The two organic plasticizers used were di-amyl phenyl acetate and benzoate respectively. Both gave substantial increases in pour susceptibility in the Mid-Continent oil base stocl; as shown bythe following" table.

TABLE III Pour sensitizers, known organic plasticizers 1 g I Pour Susceptibil- Per Cent Blend Oil Replaced by Plasticizer ity in midcontinent None 115 21 of Diamyl Phenyl Acetate 145 21 of Diamyl Phenyl Benzoate 170 The above datashow that replacing 21% of the blend oil by di-amyl phenyl acetate increased the poursusceptibility from 110 .to 145, while the same proportion of di-amyl phenyl. benzoate gave a pour susceptibility of 1'70, thus showing that both of these alkylated aromatic esters, known as commercial plasticizers, and both having no pour- EXAMPLES 5 AND 6 was used as the aromatic compound and in Exlample 6 benzene was used. In both examples chlorwax was used as the aliphatic constituent, and aluminum chloride was used as catalyst. The quantities of materials used in these two examples were as follows:

Example 5 mol. ratio mol.

1. 3 .30 335 parts chlorwax (14% Cl) 1. 0 23 130 30 parts biphenyl 2% parts AlCls Example 6 75 30 335 100 parts chlorwax (14% Cl) 1.00 .40 78 31 parts benzene -3 parts AlCls The reactions werecarried out according to this same procedure used for making pour depressors 11-1 to 4 in Example 1 and likewise, in both cases after the reaction was completed, (after about 4 hours) at F., catalyst was hydrolyzed and removed by settling off the catalyst sludge, and the condensation products were subjected to distillation under fire and steam up to a temperature of about 600 F. Both of these reactions gave high yields of attractive, green-colored, viscous oils, both of which tested as such had no pour-depressing potency,

The, pour sensitizing characteristics of these materials were tested as previously described under Example 1 by using 21% and 42% respectively of each of these materials to replace a corresponding amount of the blend oil when blending 11.5% of pour depressor B distillation product to make a pour depressor concentrate of standardized potency, and then testing the resulting concentrate for pour susceptibility in the Mid-Continent lubricating oil base stock referred to previously. The results are shown in Table IV.

It is noted from the above table that both of the wax-biphenyl and the Wax-benzene condensation products produced a very substantial increase in the pour susceptibility of the pour depressor B when used in the Mid-Continent oil,

and in spite of the fact that neither the waxbiphenyl nor wax-benzene products per se had any substantial pour-depressin properties.

It is noted that in Examples and 6 the ratio of the chlorwax to the aromatic compound is 1.3 and 0.75 respectively on a molar ratio basis, and both of these are substantially lower than normally used for preparing active pour depressors by Friedel-Crafts condensation of chlorwax with naphthalene. In this latter case, for 100 parts by weight of chlorwax, generally only or or so parts by weight of naphthalene are used, thereby giving a molar ratio of about 0.25 to 0.35.

Accordingly, one feature of the invention comprises condensing an aliphatic compound having a long aliphatic hydrocarbon chain such as chlo rinated paraflin wax or olefins corresponding thereto, with an aromatic compound such as naphthalene, phenol, benzene, biphenyl, etc., using two different proportions, in one case using at least two mols of the aliphatic compound to one mol of the aromatic compound, and in the other case, less than 1 mols of the aliphatic compound to one of the aromatic, and recovering from each reaction a relatively non-volatile distillation residue, in the one case having good pourdepressing potency, and in the other case having little or no pour-depressing potency, but good pour sensitizing characteristics, and finally adding the two different condensation products to a waxy mineral lubricating oil in controlled proportions to obtain substantially better pour-depressing and pour stability than could be obtained with a pourdepressing condensation product alone.

EXAMPLE 7 TABLE V Percent in crease in Susceptibility With Pour sensitizer I on Type of on @31 None Mid-continent oil.

Paraf. oil

Paraf. oil +2.5- Panhandle Bright Stock.

Oil A +25% mid cont. Bright Stock.

Penn 180 Neutral.-.

M id-C out. 160 Solvent Neutral.

1 The composition of the control pour depressor B cone. is: P

ercent Pour depressor B distillation bottoms 11. 5 Blend oil 88.5

I The composition of the sensitized" pour depressor B is:

Percent Pour depressor B distillation bottoms 11.5 Pour sensitizer (Ex. 5) Blend oil The above data in Table V show that pour depressor B alone had pour susceptibility values ranging from 110 to 320 as tested in the seven different oils A, B, C, D, E and F, and that when 37% of pour sensitizer was used, the chlorwaxbiphenyl pour sensitizer was used in conjunction with pour depressor B, and pour susceptibility values ranging from 180 to 350 were obtained, relatively small increases being obtained in the case of the oil base stocks in which the pour depressor alone had a pour susceptibility above 300, especially 310 or above, but very great increases in susceptibility being obtained in the case of oil base stocks in which the pour depressor alone had pour susceptibility of 150 or below.

EXAMPLES 8 To 25 Numerous other organic compounds or products consisting of mixtures of closely related compounds, were tested for pour sensitizing characteristics, and those which gave good pour sensitizing results, and on which the generalizations stated previously were based, are tabulated in Table VI, showing across from each one, the pour susceptibility obtained within a Mid- Continent lubricating oil base stock which had been tested with a range of 0.1% to 1.0% (in steps of 0.1%) of pour depressor B. In all of these tests, the amount of pour sensitizer used was the same, namely 44% of the amount of blend oil normally required to blend 11.5% of pour depressor B distillation bottom to make a concentrate having a standardized pour-depressing potency.

TABLE VI Pour Susceptibility Ex. Pour Sensitlzor Used in Midcontinent Oil None 8 'letrshydroiuriuryl phthalate..." 245 9 Glycerol laurates 240 10 Diglycol lanrate 215 11 N-butyl levulinate 175 12 Mono-ethyl ether oi diethylene glycol 165 13 l\I ono-butoxy diethylene glycol olcate 160 14..." Diamyl cyclohexanol 150 15". Diarnyl phenyl acetate 145 16..... Ethyl acetate 140 l7 Cyclohexyl stcarate e H0 18..... Tetrahydroiuriuryl oleate H0 19..." N-hexyl benzoatc 135 20... Mono-keryl bemene (00B 125 21..-" N-butyl ether 125 22 Diamyl Phenyl-(Plienyl) sulfonate. 125 Pinene 125 Decahydronaphthalcne 25 B-N-Butoxyethyl salicylotc 120 1 Benzene alkylated with chlOr-kcrosenc.

The above Table VI shows that numerous organic compounds coming within the general qualifications set forth earlier hereinabove, have good or excellent pour sensitizing effects.

EXAMPLE" 26 TABLE VII Pour Sus- Per cent Pour sensitizer Added to Mid-continent Oil 1 ceptibility 1 Containing 11.5% of Pour Depressor B distillation bottoms.

It is thus seen that even relatively small amounts of the pour sensitizer ranging from 0.10 upwards cause a very substantial increase in the pour susceptibility of even a Mid-Continent 13 lubricating oil base stock to which has already been added .115% of pour depressor B distillation bottoms.

EXAMPLE 27 In order to study the effect of a pour sensitizer on the pour stability of an 011 containing a pour depressor, a lubricating oil base stock was made by blending together 97.5 parts by volume of a Mid-Continent lubricating oil and-2.5 parts by volume of a Mid-Continent Bright Stock having 165 at 210 F. and to this blended lubricating oil base stock were added various amounts of plain pour depressor B or pour sensitized pour depressor B, the resulting blend being subjected to the pour stability test by the standard Test V procedure as described in Oil and Gas Journal, June 24, 1943, and also giving the standard A. S. T. M. pour point for comparison.

In making these tests, a pour depressor" was made up by blending 11.5% by volume of pour depressor B distillation bottoms with 88.5% of blend oil (which was a Pennsylvania type oil). The our sensitized pour depressor B was made by blending 11.5% of the same pour depressor B distillation bottoms with 70.0% of blend oil and 18.5% of pour sensitizer, which in this case was di-amyl phenyl acetate, the same one as used in Example 15. As in other cases, this pour sensitizer had no pour-depressing properties per se.

The pour stability and A. S. T. M. pour point data on the blends prepared as described above, are shown in the following table:

The above Table VIII indicates that although the pour sensitized pour depressor B showed very little difference in A. S. T. M. pour point as compared to the plain pour depressor B, yet in the stable pour point the pour sensitized product showed an astoundingly great improvement.

It is not intended that this invention be limited to the specific examples which have been given merely for the sake of illustration but only by the appended claims in which it is intended to claim all novelty inherent in the invention, as well as all modifications coming within the scope and spirit of the invention.

What is claimed is:

1. A lubricating oil composition comprising a major proportion of waxy mineral lubricating oil containing about .02% to 2.0% of each of two additives, one called a pour depressor and the other a pour sensitizer, said pour depressor consisting essentially of a Friedel-Crafts condensation product substantially non-volatile up to 600 F. under fire and steam distillation, of about 10 to parts by weight of naphthalene with 100 parts by weight of chlorinated paraflin wax having a chlorine content of about 10 to 15%, and said pour sensitizer being a fraction having an average molecular weight of about 500, obtained by amyl alcohol extraction of substantially the same type of material as said pour depressor, said pour sensitizer being also per se substantially non-volatile up to about 600 F. under fire and steam distillation and having per se substantially no pour depressing properties.

2. A composition according to claim 1 in which the pour sensitizer has been derived by solvent extraction of about 1 volume of pour depressor with 3 volumes of a solvent mixture consisting essentially of 12 parts by volume of secondary amyl alcohol and 1 part by volume of a heavy naphtha petroleum fraction.

EUGENE LIEBER. MARTIN M. SADLON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,806,735 Bennett May 26, 1931 2,081,518 Wade May 25, 1947 2,308,116 Silverman Jan. 12, 1943 2,352,213 Lieber June 27, 1944 

